In order to preserve power resources and lower overhead usage, conventional host (physical) CPUs utilize memory monitoring instructions (e.g., monitor and mwait instructions) designating a range of memory that allow the host CPU to stop instruction execution and await receipt of an event to execute. In a virtualized computing system wherein a single virtual CPU (VCPU) of a virtual machine (VM) runs on a single host CPU, the virtual machine may execute a memory monitoring instruction on the designated address range, such that the VCPU and associated host CPU are blocked from further execution and enters a wait state until there is a change to the designated memory from an event source or an inter-processor interrupt is received.
Furthermore, in a virtualized system wherein multiple VCPUs are running on a single physical CPU, execution of memory monitoring instructions by any of the multiple VCPUs causes the underlying physical CPU to stop execution and await an event, thereby resulting in an inefficient system wherein time and resources are wasted while the physical CPU is in this idle or standby mode.